Mesoscale flow variability and its impact on connectivity for the island of Hawai'i

Abstract

Understanding population connectivity is a contemporary challenge in marine ecology. Connectivity results from a combination of biological traits and physical mechanisms, at different life stages. We focus on the transport of particles around an oceanic island, simulating transport at early life stages of marine organisms. We aim to investigate through case studies how mesoscale features influence particle transport, recruitment, and connectivity. We determine particle dispersion by using an individual-based model and the flow fields derived from a regional implementation of an ocean circulation model. To understand the underlying physical processes of transport, we locate coherent structures in the flow field, identify recurrent physical features, and observe how particle transport is related to them. Our results show that the varying eddying flow increases connectivity among populations located on different sides of the island. Both the flow field and dispersal patterns are highly variable. In this scenario, eddy events influence transport in distinct ways, and the timing of release plays an important role in dispersal. Our results highlight the need for modeling studies to use hydrodynamical model flows that represent the scales of variability affecting transport and dispersion. © 2013. American Geophysical Union. All Rights Reserved.